Question: Simplify the following expression: $k = \dfrac{30t - 60s}{50t - 50} + \dfrac{60r + 40t}{50t - 50}$ You can assume $r,s,t \neq 0$.
Answer: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{30t - 60s + 60r + 40t}{50t - 50}$ $k = \dfrac{70t - 60s + 60r}{50t - 50}$ The numerator and denominator have a common factor of $10$, so we can simplify $k = \dfrac{7t - 6s + 6r}{5t - 5}$